Automatic rifle



H. O. EIANE AUTOMAT IC RlFLE Jan. 17, 1939.

Filed June l, 1936 4 Sheets-Sheet 1 Hv O. EIANE AUTOMAT I C RI FLE Jan.17, 1939.

Filed June l, 1936 4 Sheets-Sheet 2 1936 4 Sheets-Sheet 3 H. O. EIANEAUTOMATIC RFLE Filed June l,

Jan. 17, 1939.

Q/vi hun Jan. 17, 1939. ||l o. EIANE AUTOMATIC RIFLE Filed June l, 4Sheets-Sheet 4 Patented Jan. 17, 1939 UNITED STATES PATENT OFFICE 17Claims.

My invention relates to improvements in automatic hre-arms in which thebreech bolt is locked by turning its lugs into recessed seat in thereceiver and operated by the force of powder gas from the bore of therifle; and the objects of my improvements are: First, to utilize thewell known and reliable bolt action principle in conjunction withautomatic operation; second, to provide means for quick and easydismounting i() of the breech bolt mechanism for cleaning and inspectionof the bore from the breech end of the barrel; third, to provide afire-arm with straight striking firing pin, in order to attain the bestaccuracy in firing; fourth, to provide the l fire-arm with automaticwarning signal when the magazine is empty, by having the raised bolthandle obscure the line of sight; fifth, to utilize stored gas from areservoir on the expansion principle as automatic motive power insteadof operating the automatic mechanism on the impulse principle.

I attain these objects by the use of an automatic gun mechanismhereinafter more fully described and claimed having reference to theaccompanying drawings, in which Fig. 1 is a fragmentary view inelevation partly in section of the receiver with the bolt mechanism inlocked position.

Fig. 2 is a bottom plan view of the receiver,

.3o showing the magazine throat and sear box in position.

Fig. 3 is a bottom plan view of the sear spring.

Fig. 4 is a side View of the complete sear mechanisrn.

.;,5 Fig. 5 is a top plan view of the receiver with the breech vbolt inlocked position, showing the crosshead sleeve detached from one of theop erating connecting rods.

Fig. 6 is a iront end view of the receiver with parts removed.

Fig. is a rear end view of the receiver with parts removed.

Fig. 8 is a rear view of a crosshead sleeve.

Fig. 9 is a right side view of the crosshead sleeve partly in section.

Fig. 10 is a side view in elevation of the crosshead sleeve, showing theopposite side of said sleeve.

Fig. 11 is a bottom plan view of a crosshead pin, showing lockingplunger and spiral spring in detached relation.

Fig. 12 is a longitudinal vertical section of the gas cylinders andvalve mechanism connected to the rille.

Fig. 13 is a fragmentary top plan View, partly in section, of thepiston-rod and piston assembly.

Fig. 14 is an enlarged vertical section of the check-valve and housing,shown in detached relation,

Fig. 15 is a top plan view of a barbed split-key, 5 shown detached.

Fig. 16 is a cross section of the gas cylinder and valve-rod.

Fig. 17 is a bottom plan view of a control valve, showing in detachedrelation a collar and a nut. 10

Fig. 18 is a right side View of the firing pin assembly partly insection and showing certain of the elements detached,

Fig. 19 is a right side view of the bolt sleeve, shown detached. l5

Fig. 20 is a transverse vertical section taken at the bolt handle of thebreech bolt.

Fig. 21 is a bottom plan view of the breech bolt, shown detached.

Fig. 22 is a longitudinal side View of the re- 20 arm constructed inaccordance with the principles of my invention.

Fig. 23 is a top plan view of the magazine follower.

Fig. 24 is a tcp plan view of the bolt stop and 25 associated members,shown in detached relations.

Fig. 25 is a top plan view of the ejector.

Fig. 26 is a rear end View of the piston.

Fig. 27 is a rear View of a locking sleeve.

Fig. 28 is a side view of the locking sleeve, 30

Referring more particularly to Figures 1, 2 and 5, it will be seen thatthe usual receiver A, a breech bolt 2 and a bolt-operating handle orlever 3 is provided in connection with a cartridge extractor 4 and anextractor-band 5. 35

The bottom of the receiver is approximately square when viewed from theiront end although the lower corners of the bottom are slightly roundedso that the full strength of the material is retained at points wherelongitudinal passages 40 are drilled throughout the entire length of thereceiver for slidably supporting connecting rods 8 and 9.

These passages are parallel to each other and likewise parallel to thebore 1 in which the breech 45 bolt 2 operates.

The connecting rods 8 and 9 are particularly constructed at their endsso that they may be readily removed from their supports in a cross headsleeve I2 at the rear end of the receiver A 50 and radial crosshead lugsI3 and II located in front of the receiver A.

The connecting rods 8 and 9 are secured within threaded lugs IE! and II,respectively, formed on the lower rear portion of the crosshead sleeveI2. 55

The connecting rod 8 is provided with right hand threads at its rear endand left hand threads at its front end for the purpose of obtainingminute adjustment before being permanently fixed to the lug I8 by meansof solder or rivets.

The front end of the rod 8 is threaded into a radial crosshead lug I3formed on the rear end of the piston-rod I4.

The connecting rod 9 on the other hand is provided with left handthreads at its opposite ends and these threads are milled away inquarter sections, as shown at I5 (Figs. 5 and 13) at diametricallyopposite points. Likewise, the internally threaded passages in lugs I Iand I6 are cut away to correspond with the milling of the threads of theconnecting rod 8 in such a manner that when the mutilated threads on theends of the rod 9 align with the channels I5A in lug Il (Fig, 8) the rodmay be removed from its bearings in the crosshead sleeve I2 and thecrosshead lug I6. The lug I6 is shown more particularly in Fig. 13.

A thumb leaf I1 is secured to the rod 9 and is adapted to rock the rod aquarter of a turn for aligning the mutilated threads on the said rodwith the channels in the bearings or lugs II and I5.

When the thumb leaf I1 is located ln an upright locked position, thethreads at both ends of the rod 9 are engaged respectively with thethreads in their bearings, but a 90 degrees turn to the left of thethumb leaf disengages the threads at both ends and the rod can be movedforward to clear the lug II in the crosshead sleeve I2.

The front end of the connecting rod 9 beyond the lug I6 is squared toreceive a collar I8 having a complementarily formed square hole and anut I9 is threaded onto the forward end of the rod for aiding in liningup the respective threads of the rod and the lug.

The thumb leaf I1 is provided with a locking recess 2li which has asemi-circular counterbored seat into which a semi-circular collar 2I onthe end of a crosshead pin 22 turns for locking the thumb leaf againstaccidental displacement (Figs. l0 and l1).

The crosshead pin 22 is mounted in the passage 24 in the crossheadsleeve I2 and is provided with an approximately semi-circular collar 25which ts into a semi-circular recess 28 located in a boss 21 formed onthe right side of the crosshead sleeve I2, thereby insuring thecrosshead pin against lateral end play as long as the collar 25 occupiesthe recess 26.

A lever 28 is connected with the crosshead pin 22 and is provided with aweb portion for reinforcing the same.

A cylindrical sleeve 29 is formed adjacent the free end of the lever 28and provides a bearing for a lock plunger 39 which is acted upon by aspiral spring 3l for maintaining the free end of the plunger projectedfrom the sleeve 29. The axis of said cylindrical sleeve is parallel tothe axis of the crosshead pin 22 and said sleeve is located inwardly ofthe free end of the lever 28, as shown more particularly in Fig. 11.

The plunger 30 has its inner end threaded into a knurled button or head33, after which said end is riveted or secured in any approved manner toprevent the same from working loose.

It will be noted that the button or head 33 is nested within the flangeor web of the lever 28 and this web serves as a guide for the member 33and relieves the comparatively weak plunger 30 from hard knocksincidental to rough usage.

A locking sector 34 is located at the right side of the crosshead sleeveI2 and is provided with pockets 35, 36 and 31, as shown moreparticularly in Figs. 1 and 9. These pockets are adapted to receive thefree and projecting end of the plunger 3D as the lever 28 is rocked forrocking the crosshead pin 22, and these pockets in connection with theplunger 30 will maintain the lever 28 and likewise the pin 22 in aplurality of positions.

The pocket 35 in connection with the plunger 38 locks the lever 28 infull safety position, while the pocket 36 locks the lever in semi-safetyposition.

The pocket 31 will maintain the lever 28 and likewise the pin 22 infiring position.

When it is desired to release the lever 28 from one of its lockedpositions, it is only necessary to withdraw the plunger 30 by means ofthe knurled head 33. However, the pocket 38 is relatively shallow sothat when sufcient pressure is applied to the knurled head 33 theplunger 38 will slide out of the pocket, whereby the lever 28 may berocked as desired.

The pockets 35 and 36 are located within the confines of a taperedgroove 38, so that when the free end of the plunger 30 rides in thisgroove the groove will guide the plunger toward the pockets 35 and 36.

Referring more particularly to Figs. and 2l, it will be seen that thebreech bolt is provided with two locking lugs 39 and 40 at diametricallyopposite points at the front end of the bolt and a safety lug 4I isdisposed adjacent the bolt handle 3. The lug 48 is split to provide anan row groove 42 (indicated by dotted lines in Fig. 20) to permit anejector 43 (Figs. '7 and 25) to reach the head of the cartridge to beextracted. In other words, this groove is provided as a passage for theejector 43.

The rear end of the breech bolt 2 is provided with spiral cam slots 44having notches 45 form* ing neutral lock seats for the crosshead pin 22as will be presently explained.

The handle 3 is rigidly connected to the hollow breech bolt 2 betweenthe lug 4I and the slots 44.

The ring pin assembly (Fig. 18) is carried within the hollow breech bolt2 and includes a firing pin 46 provided with an arm 41 which is spacedfrom the pin and has its upper edge parallel to the axis of the pin. Theforward end of this arm is provided with a sear notch 48.

The firing pin per se is of comparatively large diameter and has atransverse passage 49 which serves as a safety lock notch for the firingpin and approximately lines up with the crosshead pin 22 when the latteris in its normal position and the firing pin is in cocked position.

A straight slot 50 extends rearwardly from the transverse passage 49 buthas less width than the diameter of the passage.

This slot is adapted to receive the flat milled section 12 of thecrosshead pin 22, and this section is adapted to move through the slotas will be presently explained.

The length of the slot 50 plus the diameter of the transverse passage 49corresponds in length to approximately three-quarters of the distancethe firing pin 46 is carried rearwardly by the crosshead pin 22 whilesaid pin moves rearwardly through the spiral cam slots 44 (Figs. 5 and21). This movement of the firing pin is utilized for striking purpose,while the remaining portion of the rearward travel is utilized forstoring up reserve power for assisting in the closing operation of thebreech bolt 2.

The central portion of the ring pin assembly is indicated at 5| and isof a smaller diameter than the firing pin per se but forms an integralportion of the firing pin 46. The front end of the section 5| is madehexagonal, as shown at 52, to fit into a complementarily formed passagein a lock collar 53. Beyond the hexagonal portion 52, the section 5| isthreaded as shown at 51 and a spiral spring 64 embraces the section 5|and abuts the outer end of a square cut threaded section 52 formed onthe sleeve 6D.

The extreme front end of the firing pin assembly includes a section 54which carries a striking point 55 at the front end.

The rear end of the section 54 is enlarged at 56 and this section isbored and threaded on the inside to receive the threaded end 51 of thesection 5|. A tenon 58 on the enlarged portion 51 meshes with a mortise59 on the collar 53. so that these parts are locked together.

The ring pin 46 is centrally bored to reduce the weight, and this boreextends from the rear end to the slot 50.

The bolt sleeve 60 is received by the firing pin 46 and has a pair ofdiametrically disposed slots 6| through which the crosshead pin passesfor maintaining the sleeve from turning to the right or left. The rearend of the sleeve is provided with an extension 63 which is for thepurpose of aiding in turning the sleeve for screwing the same inposition.

In assembling the bolt mechanism, the ring pin 45 is placed within thebolt sleeve 50 and the spring 54 is placed over the front of the firingpin in embracing relation with the section 5|.

With the rear end of the spring abutting the threaded portion 62, thelock collar 53 is placed on the outer free end of the section 5| and isreceived by the hexagonal portion 52 and is moved inwardly of thesection 5| and until it clears the threaded end 51. The member 54 isthen screwed into place on the threaded end 51 of the section 5|. Whenthe tenon 58 aligns with the mortise 59 the parts are locked togetherand maintained under pressure by the spring 64.

XlVhen the spring 64 is compressed between the member g52 and the collar53, the bolt sleeve 68 serves as a main spring shoulder for the insideof the breech bolt 2 since the threads 52 on the sleeve 6@ are screwedinto complementary threads 65 (Fig. 20) in the breech bolt 2.

The securing of the firing pin assembly within the breech bolt isaccomplished by means of a knurled head 65 on the firing pin 4B, byturning the head 6B to the right so that the arm 41 will engage the rearextension `63 on the sleeve 69 whereby the sleeve can be turned in thedesired direction.

Since the intermeshing threads 62 and 65 fit rather loosely no tools arerequired for screwing the firing pin assembly into the breech bolt.

The receiver A, breech bolt 2, extractor 4 and the cartridge magazineare well known in the art and are of the type found in the German Mauserriiie except those portions which are located at the rear of thereceiver bridge 61 and the front ends of. the lug races or grooves 68which are provided with spiral faced cams 69 (Fig. 6).

A bolt stop 10 has a knurled head 1| and is pivcted upon a screw-bolt 13carried by the receiver A. The free end of this stop or lever isprovided with a projection or prong 11, which is located within a slotformed in the left side of the receiver A.

The lever is also provided with a lug or projection 'l5 which blocks theleft lug race or groove 68 but does not normally contact with the leftlocking lug 40 of the breech bolt 2 as the rearward momentum of the saidbolt is broken by a buffer arrangement which will be presentlydescribed.

A pointed plunger 18 is adapted to engage a double acting cam-notch 82at the rear of the lever 10 for retaining said lever in position. Aspring located in a passage 85 (Figs. 5 and 7) maintains the plunger 18in engagement with the cam-notch 82, and a threaded plug 8| screwed intothe outer threaded end of the passage 89 maintains the spring inposition.

The prong or projection 11 is split as indicated by dotted lines, asshown at 83, to enable said projection or prong to ride over the ejector43.

Before inserting the breech bolt 2 into the bore T of the receiver A,the bolt stop or lever 1U is first pulled out to the left by the knurledhead 1| and the passage through which the breech bolt moves is free sothat the bolt may be pushed and turned into its forward position.

The crosshead sleeve I2 is then moved upwardly and towards the left fromthe position shown in Fig. 5 until the passage in the lug lines up withthe rear end of the connecting rod 9.

This rod can then be pulled rearwardly by the thumb leaf |1 untilstopped by contact with the lug After this the thumb leaf is then raisedto its normal locked position on the left side of the crosshead sleeve2. The last act of assembling includes the insertion of the crossheadpin 22 through the passage 24 from the right side of the crossheadsleeve l2, then through the spiral cam slot 44 and through the rightside longitudinal slot El in the bolt sleeve 69.

The .ring pin 45 is then drawn up by its knurled head 66 slightly beyondthe full cocked position to which point the transverse passage 49 alignswith the crosshead pin 22 and then said pin can be moved into place.

During these operations, care must be exercised so that the lever 28 isin a forward and upward position before the final movement takes placeof the crosshead pin 22 so that the collars 2| and 25 (Fig. 11) can passinto their respective recesses 20 and 26 after which the turning leaf orlever 28 is rocked to the rear and locked in any desired position.

At this stage of assembling the bolt mechanism is ready for action.

The flattened section 12 of the crosshead pin 22 permits the crossheadpin to pass freely back and forth through the slot 5B when the lever 28is in locked position at the locking pocket 31. This is the positiontermed ready-tore. When the lever 28 is in safety locked position., itis retained in position by the plunger 3d and the pocket 35. Thecrosshead pin cannot then move through the slot 50. or vice versa andthe ring pin is in safety locked position.

When the pocket 3B is engaged by the plunger 3D, the firing pin is thenin semhsafety locked position. When locked in either of the two lastmentioned positions the firing pin 46 is retained slightly beyond itsfull cocked position so that the full force of the compressed spring 64will rest on the crosshead pin 22 and not on the trigger or seararrangement. In other words, when the firing pin is in safety positionthe sear and trigger arrangements are free to resume their formerpositions in case the trigger is accidently pulled.

The breech bolt 2 is held in its rearward position by means ofmanipulation of the lever 10 so that the prong 11 engages the front faceof the lug 40, whereby cartridges may be loaded into the magazine 16.

Referring particularly to Figs. l, 2 and 4, it will be seen that thetrigger mechanism co-operates with a sear 85 housed in a frame or box 86which in turn is fitted into a recess in the bottom of the receiver Aand held in place by a pin 91.

A pair of lugs 88 project from the bottom of the receiver A and arespaced apart to accommodate the sear box 86, and the pin 91 is supportedby said lugs and received by the passage 89 in the walls of said searboX.

The sear box 86 is so constructed that it will directly locate a pin 90upon which the sear 95 is pivoted as near as possible to the arm 41,depending upon the firing pin 49.

A rocker arm 9| is pivoted on the lower end of the sear 85 by means of apin 92 located near the longitudinal center of the arm.

A push rod 94 is pivoted to the rocker arm 9| in front of the Searmember 85 by means of a pin 93 and urged in one direction by a spiralspring 95 connected between the front of the rocker arm 9| and the searbox 86.

The spring 96 maintains the sear 85 in contact with the arm 41.

An elongated opening 91 is provided in the bottom of the receiver Athrough which the push rod 94 projects and makes contact with aneccentric groove 98 (Figs. 20 and 2l) disposed on the underside of thebreech bolt 2 and so arranged that when the breech bolt is in lockedposition the upper end of the push rod 94 rests in the deepest end ofsaid eccentric groove and normal contact is then established between therear end of the rocker arm 9| and the inside extension 99 of the trigger|00.

When the breech bolt 2 however, is in unlocked position the rocker arm9| is disengaged from the extension 99. 'I'his extension is maintainedin a rearward position ready for contact by a spring Referring moreparticularly to Fig. 1, it will be seen that a receiver lug |02 locatedat the front of the receiver A supports a buier housing |03 and thishousing consists of two semi-circular sections which are held togetherby semiannular ribs |04, mounted in an annular groove formed in the lug|02.

These semi-circular sections are secured to the lug by means of aflanged guide tube |05 which is screwed into the lug |02.

A steel washer |01 is placed within the housing |03, and behind thissteel washer, soft rubber or cork washers are placed (not shown) toabsorb the shock of the moving parts constituting the automaticmechanism of the gun when the buier head |08 on the rear end of thepiston-rod i4 comes into contact with said steel washer.

The piston-rod I4 is hollow and slides over` the guide tube |06.

A ball-head ||0 on the forward end of the piston-rod I4 is mounted in aball-socket in a piston |09.

The ball-head ||0 is faced flat on diametrically opposite sides (notshown) to permit insertion into the socket (Figs. 13 and 26), and thepiston |09 given a quarter turn with respect to the rod I4, and retainedin that position by means of a split lock sleeve ||2 inserted at therear end of the piston |09 in` such manner that the extensions or prongs||3 of which there are two, will take the place of the milled oiportions of the ball-head ||0 which corresspond to the entrance to thesocket ||I, shown in Fig. 26.

A pair of ridges or projections ||4 (Figs. 21 and 28) expand into aninner circular groove ||5 in the rear of the piston |09 and retain thelock sleeve ||2 in its proper position.

The piston |09 is provided with a plurality of bull rings ||6 and a likenumber of split expansion rings ||1, and these rings are held inposition by means of a threaded nut I8 screwed onto the front end ofsaid piston.

The piston |09 slides within a cylinder ||9 attached to a. projection orvalve housing which is integral with a rifle barrel '|2|.

A spiral action spring |22 embraces the cylinder ||9 and is secured atits front end by means of slots |23 of which there are two, located inlugs |24 (Figs. 12 and 16) through which the end of the spring ispassed. The rear end of the spring |22 is secured in slots |25 locatedin the lugs |3 and |6 (Figs. 12 and 13).

The spring |22 is bent at its rear end to point forward and at its frontend to point rearward, and split-keys |26 provided with barbs |21inserted into the slots |23 and |25 to prevent the ends of the spring|22 from working loose.

The barbed split-key |26 (Fig. 15) is shaped as part of a circle and ofa diameter corresponding to that of the action spring |22.

A passage |29 communicating between the cylinder ||9 and the bore |2|Ain the barrel |2| is provided with a control valve |29 tp regulate theopening thereof and to provide means for closing of said passage when sodesired.

A spring-pressed check-valve |30 is located in the passage |28 whichnormally closes said passage until opened by gas pressure from the bore|2|A of the barrel |2|` The check-valve |30 is operatively supported ina housing |30A and held to its seat by pressure of a spiral spring |30B(Fig. 14). A plurality of vents |30C pass through the valve-housing |30Afor passage of gas when in operation.

A cylindrical gas-reservoir |3| is attached by means of screw threads tothe valve-housing or projection |20 (Fig. 12), and is in communicationwith the bore |2|A and the cylinder H9.

When gas enters the cylindrical reservoir |3|, a piston |32 is forced toyieldingly move outward against pressure of a spiral spring |32A locatedin front of said piston, and uncovers a relief port |32B when excessivepressure accumulates in said reservoir. A collar |32C limits the inwardmovement of the piston |32 against the action of the spring |32A.

All valves are of Well known and tried patterns, so they require nodetailed descriptions.

The barrel |2| is provided with a cartridge chamber at its rear end (notshown) and into this chamber an initial cartridge is placed throughmanual operation of the breech bolt 2 by means of the bolt handle 3.

When this cartridge is red the bullet or projectile is forced outthrough the bore |2|A by expanding gases and when the projectile hasuncovered the communicating passage |29 a portion of the expanding gasesforces the check- Valve |30 open and fills the cylindrical reservoir |3|and simultaneously exerts pressure against the two pistons |09 and |32,but as the piston |09 is connected to the breech bolt mechanism with itsinherent inertia in addition to pressure exerted from the bore |2|A, thepiston |32 therefore moves in advance of the former and at the same timeincreases the volume capacity of said reservoir.

When the pressure in the bore |2|A is decreased sufliciently, the valve|30 will automatically close the communicating passage |28 and theentrapped expansive gas aided by pressure from the spring-pressed piston|32 will cause the piston |09 connected to the breech mechanism to moveout through the cylinder ||9 and simultaneously pull or stretch out theaction spring |22.

As the piston |09 advances out through the cylinder ||9 the stored orentrapped gas pressure decreases, which in turn causes the piston |32 toclose up on the receding gases by reason of stored power in the spiralspring |32A and thereby prolongs the effective expansive power of thegases.

As the crosshead pin 22 carried by the crosshead sleeve |2 moves throughthe spiral slots 44 rotary motion to the breech bolt 2 is therebyeffected, and as a cam |33 located at the inner end of the bolt handle 3(Fig. 5) engages a rearwardly faced cam |34 located at the rear of thereceiver bridge 61, the tightly expanded cartridge-shell gripped by theextractor 4 is unseated from its chamber.

At this stage of rotary motion, the crosshead pin 22 has reached therearward limit of its travel through the spiral slots 44 andsimultaneously carried along the firing pin 46 to its full travel limitwith respect to the breech bolt 2, and the pin 22 from then on exertsonly rearward pressure to the bolt 2, while means for Y effecting acontinuous rotary movement of said bolt is shifted in co-ordinated orderto the forward locking lugs 39 and 40 which slide along in the spirallyfaced cam grooves 69 until the pin 22 is seated in the neutral lock seatnotches 45.

At the point where the crosshead pin 22 comes to rest in the lock seatnotches 45 the breech bolt 2 has completed its rotary movement and thelugs 39 and 40 entered into the regular longitudinal lug races orgrooves 68.

It will be noted that the pitch of the spirally faced cam grooves 69corresponds closely to the pitch in the spiral cam slots 44.

As the breech bolt 2 approaches its rearward travel limit, the emptycartridge-shell is ejected by the ejector 43 and the rearward momentumof the breech bolt and its connected automatic mechanism graduallybroken by means of the buffer arrangement shown in Fig. 1.

Referring again to Fig. 12, it will be seen that the cam rod |31 isprovided with a return bend |38 adapted to fit the inside wall of thecylinder ||9 and located in the path of the piston |09.

When the piston |09 approaches its rearward travel limit the return-bend|38 is encountered and a rod |31 provided with a cam |39 carried alongwhich causes said cam to impart rocking movement to a rocker arm |40which in turn lifts an exhaust valve |4| off its seat, and the gases inthe cylinders ||9 and |3| escape out to the atmosphere by way of aplurality of vents |42.

As the breech bolt 2 commences on its return stroke by action of storedpower in the action spring |22, a loaded cartridge is raised up in frontof the bolt by action of a magazine spring |35 attached to a follower|36 and carried along toward the chamber in the barrel |2| (not shown)As the breech bolt 2 and its connected moving parts travel along on itsreturn stroke, momentum is gained and this force is utilized to give thebolt 2 a powerful turning movement When the cam |33 engages the cam |34and thus, effect unlocking of the seats 45 from the crosshead pin 22.

At a point where the crosshead pin 22 enters the spiral cam slots 44from their rear ends, a portion of the stored energy in the spring 64 isutilized to assist in the closing movement of the breech bolt 2, duringaction of cartridge seating when the lugs 39 and 40 engage the seatingcams |46 (Fig 6).

When the lugs 39 and 40 commence to engage their respective lockingseats |41, first then, does the sear 85 engage the notch 48, located onthe arm 41 (Fig. 18).

During the remaining part of the closing action of the breech bolt 2,the forward part of the buff-czl `head |08 (Fig. l2) returns the cam rod|31 to its forward and normal position, and the exhaust valve |4| isclosed by action of the spring |4IA, and the fire-arm is again ready foraction.

Referring again to Fig. 16, it will be seen that the guides |43 areraised a trifle above the cam rod |31 so as to prevent the action spring|22 from rubbing against said rod.

Referring again to Figs. 1 and 2, it will be seen that a vertical groove|49 is provided in the rear wall of the magazine 16, and into thisgroove, an extension |50 located on the rear end of the follower |36(Fig. 23) is adapted to operate and directly retain the breech bolt 2 ina retracted and inoperative position, and simultaneously give warning bymeans of the raised bolt handle 3 that the magazine is empty.

In Fig. 18, dotted line |48 indicates distance n traveled by the firingpin 46 While giving off its stored surplus power in co-operative actionfor closing of the breech bolt 2.

This important and effective arrangement is accomplished by the simplemethod of providing, first, an extra strong main spring 64, andsecondly, by increasing the rearward travel of the firing pin 46 withrespect to the breech bolt 2, and lastly, by xing of the point at whichthe sear 85 engages the notch 48, located on the arm 41 of the firingpin 46.

Referring more particularly to Fig. 5, it will be seen that two cams |33and |34, the first mentioned located at the inner end of the bolt handle3, and the latter located in the rear part of the receiver bridge 61,are double-acting but continuous and of different pitch and fordifferent purposes. The front portions of the cams |33 and |34 are ofnarrow pitch and are designed to give a powerful extraction pull whenthe cam |33 rotates against the rearward faced cam |34 while the breechbolt 2 is on its way out, but the rear portions of the cams have alonger pitch and are designed to give a powerful turning movement of thebreech bolt on .its forward travel in order to unlock itself from thecrosshead pin 22 seated in the neutral lock seats 45, which are a trifledeep and requires force to effect unlocking.

Additional cams |44 and |45 (Figs. '1 and 20) each have a pitchcorresponding to the rear portions of the cams |33 and |34 and cooperatewith the latter to impart rotary movement to the breech bolt 2.

Referring to Figs l and 22, it will be seen that a thumb guard |5|attached to the rear end of the receiver A is provided to protect thehand of the operator from getting into the path or sweep of the breechbolt 2.

Referring more particularly to Figs. 17 and 22, it will be seen that thecontrol valve |29 is provided with a spring turning leaf |52 which isadapted to operate in a sunken quarter section dial |53, which in turnis adapted to retain said turning leaf in any position within the limitsof said dial.

In Fig. 17, the square collar |54 and the nut |55 prevent lateral endplay to the valve |29.

Referring again to Figs. and 7, it will be seen that the longitudinalpassages 6 are counter bored at their rear ends to accommodate the lugsI0 and of the crosshead sleeve I2 (Figs. 1 and 8), while the middlesections of said passages are reamed out (not shown) preferably withexpansion reamers, but leaving a sufficient portion thereof at each endto provide bearings for the rods 8 and 9.

I do not intend to limit my invention to any particular size or style ofguns or fire-arms, nor to the exact drawings and descriptions as hereingiven, as many changes can be made without departing from the principlesinvolved.

Having thus described my invention what I claim as new and desire tosecure by Letters Patent is:

1. In an automatic firearm, a receiver having a longitudinal bore, abreech bolt in the bore and provided with spiral cam slots at the rearend, a crosshead sleeve slidably carried by the receiver and embracingthe slotted end of the breech bolt, a rockable pin carried transverselyby the sleeve and passing through the cam slots, a ring pin within thebreech bolt having a keyhole-shaped slot also receiving the rockablepin, an arm depending from the ring pin and provided with a sear notch,a sear mechanism having a sear engaging the notch, said rockable pinco-operating with the keyhole-shaped slot for effecting cooking movementof the firing pin, means for retaining the iiring pin in a safety lockedposition when said rockable pin is shifted to a predetermined positionwith respect to said crosshead sleeve, means for rocking and retainingthe pin in prefixed positions with respect to said sleeve, said meanscomprising a turning leaf on the pin, a spring-pressed locking plungercarried within the turning leaf, an externally guided head on theplunger, a semi-circular collar on the pin, a semicircular recess on thesleeve to receive the collar, and a lock sector with locking pockets onsaid sleeve to receive the locking plunger when brought into alignment,and means for rotating and reciprocating the breech bolt, substantiallyas described.

2. In an automatic firearm, a receiver having a bore, a reciprocatingbreech bolt in the bore, a reciprocating crosshead sleeve for moving thebolt, a rockable pin carried by the sleeve, a pair of action rods, onerod being threaded and fixed to the sleeve, the second rod beingconnected to the sleeve by demountable means comprising a xed turningleaf on the rod, a semi-circular recessed seat on the leaf, asemi-circular collar on the rockable pin adapted to engage the seat andlock the leaf to the sleeve, interrupted threads on the rod engageablewith similar cut threads in the sleeve and full threads and interruptedthreads respectively at the opposite ends of the rods for furtherconnections, means connected with the rods and acted on by the eX-plosive gases in the barrel of the firearm for causing rearward movementof the rods and sleeve, said bolt having cam slots to receive the pin, aring pin having a slot to receive the pin likewise, for causing the boltto be rotated and simultaneously eiect the cocking movement of thefiring pin, the walls of the bore having cam grooves, lugs on the boltand disposed within the grooves for causing further rotation of thebolt, all substantially as shown and described.

3. In an automatic rearrn, a ring pin provided with a transverse slot, asleeve on the pin having diametrically opposed slots aligning with theslots in the pin, a crosshead pin received by the aligned slots, areceiver provided with a bore, a bolt in the bore receiving the ringpin, said bolt having cam slots receiving the crosshead pin, means forcausing reciprocation of the bolt and likewise the firing pin, thecrosshead pin causing relative movement between the ring pin and saidbolt.

4. In an automatic firearm, a receiver having a bore, a breech boltmounted for rocking and reciprocating movement in the bore, the walls ofthe bore being provided with cam grooves, diametrically disposed lugs onthe bolt received by the grooves, a safety lug on the breech bolt, aspring-pressed ring pin located within the bolt and provided with atransverse sectional passage and a longitudinal slot extending from saidpassage which is narrower than said passage, a crosshead sleeve slidablymounted on the receiver, a` crosshead pin rockably mounted transverselyof the sleeve and received by the passage in the firing pin, wherebysaid crosshead pin may be rocked, said crosshead pin having a reducedsection to be received by the slot in the firing pin to permitlongitudinal movement of the two engaged parts, the breech bolt beingprovided with cam slots at the rear end thereof and receiving thecrosshead pin, said bolt having seats at the ends of the cam slots sothat when the crosshead pin is received by said seats said pin will belocked therein, co-operating means between the receiver and the breechbolt for causing rocking of the breech bolt and for moving the seatsaway from the crosshead pin, and means for causing reciprocation of thebreech bolt.

5. In an automatic rearm, a receiver having a longitudinal bore, amagazine having a throat opening into the bore, the .receiver having apair of lug grooves, a pair of spiral faced cam grooves and a pair ofrecessed locking seats, the lug grooves being connected with the seatsby the cam grooves, a pair of longitudinal passages extending throughthe solid walls of the receiver at opposite sides of the throat openingand parallel to the bore, a complementary action rod comprising a pairof parallel spaced rods in its rear end and a singular piston-rod in itsfront end slidably mounted in the passages, a crosshead sleeve providedwith threaded lugs attached to the rear ends of said action rod, abreech bolt provided with locking lugs at the front end and spiral cam.slots with locking seats at the rear end, a rockable crosshead pincarried transversely by the sleeve and passing through the slots in thebolt, a piston universally joined to the front end of the piston-rod,said bolt adapted to be rotated and reciprocated in the bore and furtherrotated when the lugs engage the cam grooves, the rearward movement ofthe bolt while rotating causing the seats at the ends of the cam slotsto receive the crosshead pin and lock the seats onto the pin, stationarycams on the rear end of the receiver and means on the bolt engageablewith the cams for effecting release of the seats from the pin at the endof the forward or return movement of the breech bolt, and means forcausing the piston and action rod to reciprocate when acted on by directgas pressure from a closed reservoir, al1 substantially as shown anddescribed.

6. In an automatic firearm, a firing pin, a stem projecting from` thepin, a sleeve mounted on said pin and provided with a shoulder at theinner end thereof, a collar on the outer end of the stem, a spiralspring on the stem and abutting at the ends thereof on the shoulder andsaid collar, a iiring point threaded onto the outer end of the stem andinterlocking means between the stem and collar and collar and ringpoint, said interlocking means comprising a hexagonal faced portion ofthe stem adapted to assembling of said sleeve and spring and a lockcollar having a complementary passage adapted to engage said hexagonalfaced portion and interlocking tenon and mortise between said collar andfiring point.

'7. In an automatic firearm, a receiver having a bore, a breech bolt inthe bore and provided with an eccentric groove, a sear mechanismincluding a frame connected to the bottom of the receiver, a searpivoted in the frame, a rocker arm pivoted to the sear, a contact rodpivoted at one end to the arm, a spring acting on the arm for causingthe other end of the rod to seat in the groove, a trigger mechanismhaving contact with the rocker arm, rotary movements of the belt causingreciprocation of rod for causing release of the rocker arm from thetrigger mechanism.

8. In an automatic rearm, a receiver having a bore, a breech bolt in thebore and provided with an eccentric groove, a sear mechanism including aframe connected to the bottom of the receiver, a sear pivoted in theframe, a rocker arm pivoted to the sear, a contact rod pivoted at oneend to the arm, a spring acting on the arm for causing the other end ofthe rod to seat in the groove, a trigger mechanism having contact withthe arm, rotary movements of the bolt causing reciprocation of the rodfor causing release of the rocker arm from the trigger mechanism, afiring pin in the bolt, an arm depending from the firing pin andprovided with a notch, said sear adapted to engage the notch untilreleased by means of pressure on the trigger, substantially asdescribed.

9. In an automatic firearm, a receiver provided with a bore and a slotin its left side wall, a barrel connected with the receiver, a magazinehaving a throat leading into the receiver, a follower in` the magazine,a spring for urging the follower toward the throat, a vertical groove inthe rear wall of the magazine, a rearward extension on the follower andadapted to travel in the groove, a breech bolt in the bore, an actionrod operatively connected to the breech bolt, a main action springconnected to said rod and urging the bolt in a forward direction, saidextension adapted to engage in direct contact with the bolt and retainsaid bolt in an inoperative position beyond the rear wall of themagazine, a lever pivotally mounted in said slot and provided with aninward projecting prong which communicates with said bore, said leveradapted to engage and retain the bolt in its retracted position by meansof manual pressure to facilitate the loading of cartridges into saidmagazine, and self-acting release between said lever and bolt by meansof said action spring coincident with release of said manual pressure.

10. In an automatic rearm, a receiver having a bore, a hollow breechbolt in the bore, means including a crosshead sleeve for causingrotation and reciprocation of the bolt in the bore,

a ring pin in the hollow bolt, a dependent arm on the firing pinprovided with a scar notch, a spring adapted to be placed undercompression in the hollow bolt for urging the firing pin in onedirection, a sear mechanism, a portion of the energy stored in thecompressed spring being utilized for co-operative assistance in therotary closing movement of said breech bolt prior to engagement betweensaid sear notch and said sear mechanism, and means for causingreciprocation of said crosshead sleeve.

ll. In an automatic firearm, a receiver having a bore, a hollow breechbolt in the bore, means including a crosshead sleeve for causingrotation and reciprocation of the bolt in the bore, a ring pin in thehollow bolt, a dependent arm on the firing pin provided with a searnotch, a spring adapted to be placed under compression in the hollowbolt for urging the nrlng pin in one direction, a sear mechanism, aportion of the energy stored in the compressed spring being utilized forco-operative assistance in the rotary closing movement of said breechbolt prior to engagement between said sear notch and said searmechanism, means for causing reciprocal movement of the crossheadsleeve, the bolt having spiral slots, the walls of which forming cams,the last mentioned means including the cams and a crosshead pin passingthrough the slots, said pin being rockable in the crosshead sleeve.

l2. In an automatic firearm, a receiver having a bore, a hollow breechbolt in the bore, means for rotating and reciprocating said bolt, meanson the receiver including a split buffer housing provided with inwardcrimped edges for rotating cushioning material therein and engageablewith the reciprocating means at the limit of the rearward movement ofsaid breech bolt.

13. In an automatic firearm, a receiver having a bore provided with lugraces or grooves, a hollow breech bolt in the bore provided with lugs,means for rotating and reciprocating said bolt, means on the receiverincluding a split buffer housing provided with inward crimped edges forretaining cushioning material therein and engageable with thereciprocating means at the limit of the rearward movement of the bolt, alever pivoted on the receiver and having a projection extending into andblocking one of said lug races, said lever adapted as a reserve stop toengage directly a lug of said breech bolt upon failure of saidreciprocating means.

14. In an automatic rearm, a receiver, a barrel provided with a boreattached thereto, a breech bolt turnable and reciprocable in thereceiver, a pair of longitudinal passages extending through thereceiver, a crosshead sleeve, a pair of rods slidably mounted in thepassages and detachably connected to the sleeve, a rockable pinconnecting the bolt with the sleeve, an eX- tension projecting from thebarrel, a cylinder connected to the extension, said extension having apassage connecting the cylinder with the bore, a spring-pressed valve inthe passage normally closing said passage until gas pressure from thebore opens the valve for admission of gas to the cylinder, aspring-pressed piston in the cylinder, and means connecting the rodswith the piston, said means comprising a piston-rod provided with a pairof internally threaded lugs at one end for connecting with the rods andthe other end of the piston-rod provided with a ball-head adapted foriiexible connection with a ball-socket in said piston, all substantiallyas shown and described.

15. In an automatic firearm having a receiver, a barrel provided with abore attached to the receiver, a crosshead sleeve, a pair of action rodsconnected to the sleeve and slidably mounted in the receiver, a rockablepin connecting the bolt with the sleeve, an extension projecting fromthe barrel, a cylinder connected to the extension, said extension havinga passage connecting the cylinder with the bore, a springpressed valvein the passage normally closing said passage until gas pressure from thebore opens the valve for admission of gas to the cylinder, aspring-pressed piston in the cylinder, a piston-rod connecting saidpiston with the action rods, a spring-pressed exhaust valve in theextension, a passage communicating between the cylinder and theatmosphere, said exhaust valve normally closing said last mentionedpassage, a pivoted rocker arm adapted to contact with said exhaustvalve, a cam-rod slidably mounted in guides on the cylinder and hav- Iing its cam end in operative contact with said rocker arm, and means onthe other end of the cam-rod engageable with means on the pistonrod foractuating and timing the opening and closing of said exhaust valve atpredetermined points in relation to the position of the piston in saidcylinder.

16. In an automatic firearm having a receiver, a barrel provided with abore attached to the receiver, a breech bolt turnable and reciprocablein the receiver, a crosshead sleeve, a pair of action rods connected tothe sleeve and slidably mounted in the receiver, a rockable pinconnecting the bolt with the sleeve, an extension projecting from thebarrel, a cylinder connected to the extension, said extension having apassage connecting the cylinder with the bore,

a spring-pressed valve in the passage normally closing said passageuntil gas pressure from the bore opens the valve for admission of gas tothe cylinder, a spring-pressed piston in the cylinder, a piston-rodconnecting said piston with said action rods for actuating the movementof said breech bolt, a second cylinder forming a gas reservoir connectedto the extension and communicating with said passage and saidfirstmentioned cylinder, a relief port in the second cylinder, and aspring-pressed piston in said second cylinder adapted to be moved inadvance of the first-mentioned piston and adapted to act as cushion andrelief valve when excessive pressure accumulates in the cylinders, allsubstantially as shoWn and described.

1'7. In an automatic firearm, a receiver having a bore, a breech boltturnable and reciprocable in the bore, a crosshead sleeve embracing therear portion of the breech bolt, a rockable pin connecting the bolt withthe sleeve, a barrel provided with a bore attached to the receiver, apair of longitudinal passages extending through the receiver, a pair ofaction rods slidably mounted in the passages and detachably connected tosaid crosshead sleeve, means including a gas-reservoir for causingrotary and reciprocating movements to said breech bolt, a cartridgemagazine, a throat opening communicating between the magazine and thebore in the receiver, a cartridge extractor connected by means of a bandto said breech bolt, a pivoted cartridge ejector mounted in thereceiver, and a bolt-handle or lever projecting from said breech boltadapted for manual operation of said bolt in effecting initial cartridgeloading into the bore of the barrel from said magazine.

HALVOR OLSEN EIANE.

